Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Lithium ion batteries are commonly used in electronics. Electrochemically, Li+ is a small, light, and mobile cation. Lithium has contributed to significant advances in portability, capacity, and rechargeability of lithium ion batteries. For example, lithium's high mobility in olefinic carbonates and polyethylene oxide has made for efficient electrolytes. In comparison to other alkali metals, lithium readily intercalates with graphite to make reversible carbon and graphite electrodes. Also, lithium metal oxide chemistry has provided various oxide matrices with reversible lithium ion redox and transport.
The popularity of lithium batteries, however, has raised concerns regarding supply and sustainability, since natural, easily extractible sources of lithium are limited. Also, because the lithium ion battery market is anticipated to grow dramatically, there has been an active search to identify other natural sources of lithium compounds and alternatives to lithium based batteries.
More abundant alkali elements such as sodium have been investigated as substitutes for lithium, but lithium replacement has been challenging. For example, in graphite electrodes, sodium does not intercalate as easily as lithium. Also, while sodium metal oxides have been researched for use as electrodes, the mobility of sodium in oxide matrices has been observed to be lower than lithium in corresponding lithium oxides. The present disclosure appreciates that implementing other alkali metals as substitutes for lithium ion battery technology may be a complex undertaking.